Apparatus system and method of depicting plume arrival times

Computer implemented methods and systems work cooperatively to calculate and display plume arrival time of a CBR contaminant and to alert responders to take action, associated with mitigating the CBR contaminant. The methods and systems comprise: performing, plume arrival time operational use routines, including: sensing an unknown CBR contaminant released in a geographic area of interest and then, over a communications network, alerting and causing responders to mitigate the CBR contaminant by displaying realtime graphics on handheld computer implemented graphics devices, as well as host computers and distributed computers, showing current and predicted paths of plumes of the CBR plume, by estimating an initial source location of the unknown contaminant, calculating and displaying on graphic displays, an arrival time of at least one or more plumes associated with the CBR contaminant.